TM 5-623
CHAPTER 4
MAINTENANCE AND REPAIR (M&R) GUIDELINES
that can be used to determine whether variation exists.
4-1. Introduction
When a PCI value of a sample unit in the section is less
M&R needs and priorities are highly related to the PCI,
than the sample unit critical PCI value, a localized
since the PCI is determined by distress information
random variation exists. For example, if the mean PCI of
which is a key factor in establishing pavement M&R
a section is 59, any sample unit with a PCI of less than
requirements. This chapter describes how to do a
42 should be identified as a localized bad area by circling
payment evaluation, how to determine feasible M&R
"Yes" under item 2a on the form. This variation should
alternatives, and how to establish M&R priorities. These
be considered when determining M&R needs.
guidelines should be based on the PCI, with
Systematic variation occurs whenever a large,
consideration given to other important factors including
concentrated area of a section has significantly different
pavement load-carrying capacity.
Nondestructive
condition. For example, if traffic is channeled into a
pavement testing techniques may be used in this load-
certain portion of a large parking lot, that portion may
carrying capacity evaluation. A specific M&R alternative
show much more distress or be in a poorer condition
can often be selected for a pavement section that is in
than the rest of the area. Whenever a significant amount
very good or excellent condition without a life-cycle cost
of systematic variability exists within a section, the
analysis. In cases where a life-cycle cost analysis is
section should be subdivided into two or more sections.
necessary to select among feasible alternatives, the live-
In that example being considered (fig 4-1) there was no
cycle cost analysis method described in chapter 5 should
localized random or systematic variation, so "No" was
be used.
circled at both lines 2a and 2b.
c. Rate of deterioration of condition-PCI. Both the
4-2. Pavement evaluation procedure
long and short-term rate of deterioration of each
Evaluation is performed on a section-by-section basis
pavement section should be checked. The long-term
since each section represents a unit of the pavement
rate is measured from the time of construction or time of
network that is uniform in structural composition and
last overall M&R (such as an overlay). The rate is
subjected to consistent traffic loadings. It is necessary to
determined as low, normal, or high using figures 4-3
make a comprehensive evaluation of pavement condition
through 4-6. The figures are for the following four
before rational determination of feasible M&R
payment types respectively: asphalt concrete (AC)
alternatives can be made. A step-by-step description of
pavements, AC overlay over AC pavements, Portland
how to complete the DA Form 5147-R, Section
cement concrete (PCC) pavements, and AC overlay over
Evaluation Summary (fig. E-3) is given below. An
PCC pavements. Development of the curves delineating
example of a completed DA Form 5147-R is shown at
the low, normal, and high rate of deterioration was based
figure 4-1.
on field data from Fort Eustis, Virginia. For example, an
a. Overall condition. The PCI of a pavement
AC pavement that is 20 years old with a PCI of 50 is
section describes the section's overall condition. The
considered to have a high long-term rate of deterioration
PCI, and thus the section condition rating (e.g., good or
with respect to other AC pavements.
Short-term
very good), is based on many field tests and represents
deterioration (i.e., a drop in PCI during the last year)
the collective judgment of experienced pavement
should also be determined since a high short-term
engineers. In turn, the overall condition of the section
deterioration rate can indicate the imminent failure of a
correlates highly with the needed level of M&R. In figure
pavement section (fig. 4-7). In general, whenever the
4-1 the PCI of the section under consideration was 15,
PCI of a section decreases by 7 or more PCI points in a
so that number was recorded on line 1 and the
year, the deterioration rate should be considered high. If
appropriate rating-"very poor"-circled.
the loss in PCI points is 4 to 6, the short-term
b. Variations of the PCI within section.
PCI
deterioration rate should be considered normal. It
variation within a section can occur on a localized
random basis, and/or a systematic basis. Figure 4-2,
which was developed from field data, gives guidelines
4-1
Previous Page
